Method and apparatus for providing dynamic multi-stage signal amplification in a medical device

Abstract

Methods and apparatus for providing multi-stage signal amplification in a medical telemetry system are provided.

What is claimed is: 
     
       1. A method of processing signals from an analyte sensor, comprising:
 coupling a first amplifier to a second amplifier and a signal source; 
 comparing signals at an output terminal of the second amplifier to a predetermined threshold value; and 
 processing a signal associated with the signals at the second amplifier output terminal when another signal at the second amplifier output terminal exceeds the predetermined threshold value. 
 
     
     
       2. The method of  claim 1 , wherein the first amplifier includes a transimpedance amplifier. 
     
     
       3. The method of  claim 1 , wherein the first amplifier includes an inverting input terminal. 
     
     
       4. The method of  claim 3 , further including coupling a reference signal source to a noninverting input terminal of the first amplifier. 
     
     
       5. The method of  claim 1 , wherein a first output signal from the first amplifier is a predetermined ratio of a second output signal from the second amplifier. 
     
     
       6. The method of  claim 5 , wherein the first output signal is associated with a signal from the signal source. 
     
     
       7. The method of  claim 5 , wherein the first output signal and the second output signal are associated with a monitored analyte level. 
     
     
       8. The method of  claim 1 , further including configuring the signal source to receive one or more signals associated with a monitored analyte level from the analyte sensor. 
     
     
       9. The method of  claim 1 , further including operatively coupling the signal source to a glucose sensor. 
     
     
       10. The method of  claim 9 , wherein the glucose sensor comprises a plurality of electrodes including a working electrode, wherein the working electrode comprises a glucose-responsive enzyme and a mediator, wherein at least one of the glucose-responsive enzyme and the mediator is chemically bonded to a polymer disposed on the working electrode, and wherein at least one of the glucose-responsive enzyme and the mediator is crosslinked with the polymer. 
     
     
       11. An apparatus, comprising:
 a first amplifier operatively coupled to a signal source; 
 a second amplifier operatively coupled to the first amplifier; and 
 a processing unit operatively coupled to one or more of the first amplifier, and the second amplifier, the processing unit configured to compare signals at an output terminal of the second amplifier to a predetermined threshold value, and configured to process a signal associated with the signals at the second amplifier output terminal when another signal at the second amplifier output terminal exceeds the predetermined threshold value. 
 
     
     
       12. The apparatus of  claim 11 , wherein the first amplifier includes a transimpedance amplifier. 
     
     
       13. The apparatus of  claim 11 , wherein the first amplifier includes an inverting input terminal. 
     
     
       14. The apparatus of  claim 13 , further including a reference signal source operatively coupled to a noninverting input terminal of the first amplifier. 
     
     
       15. The apparatus of  claim 11 , wherein a first output signal from the first amplifier is a predetermined ratio of a second output signal from the second amplifier. 
     
     
       16. The apparatus of  claim 15 , wherein the first output signal is associated with a signal from the signal source. 
     
     
       17. The apparatus of  claim 15 , wherein the first output signal and the second output signal are associated with a monitored analyte level. 
     
     
       18. The apparatus of  claim 11 , wherein the signal source is further configured to receive one or more signals associated with a monitored analyte level from an analyte sensor. 
     
     
       19. The apparatus of  claim 11 , wherein the signal source is operatively coupled to a glucose sensor. 
     
     
       20. The apparatus of  claim 19 , wherein the glucose sensor comprises a plurality of electrodes including a working electrode, wherein the working electrode comprises a glucose-responsive enzyme and a mediator, wherein at least one of the glucose-responsive enzyme and the mediator is chemically bonded to a polymer disposed on the working electrode, and wherein at least one of the glucose-responsive enzyme and the mediator is crosslinked with the polymer.